North Korea remains isolated and in fear of an Iraq-style invasion from the United States.

President Kim Jong Il, son of Kim Il Sung, and head of the only dynasty in the history of communism

International crisis talks continue over the regime's nuclear weapons programme.

But This World has uncovered evidence of another more chilling evil: that North Korea is testing new chemical weapons on women and children.

Hundreds of thousands of people are imprisoned without charge. It's not because they have committed a crime. It is because their relatives are believed to be critical of the regime and so they are punished.

According to President Kim Jong Il, the bad blood and seed of any dissident must be rooted out down to three generations.

Forced labour and starvation rations ensure that prisoners do not escape. Those who try to are publicly executed.

But this is not the North Korea the government wants the world to see. The authorities go to great lengths to equip all foreign intruders with "minders" and monitor their every move.

Former workers' party official, Sun-ok Lee, was accused of falsifying accounts and tortured in prison

The This World team were scrupulously guarded. The answers could only be found outside North Korea itself.

Reporter, Olenka Frenkiel, hears testimonies from victims of the secret camps who have since fled to South Korea or the United States. And most shocking of all, she tracks down one of the perpetrators.

Kwon Hyok, a former North Korean army intelligence officer, was also chief guard at "Prison Camp no. 22". For the first time on camera, he describes specially-made glass gas chambers used for human experimentation.

This World asks: if a deal is reached with North Korea about its nuclear weapons, should it be allowed to keep their gas chambers?

Access to Evil was broadcast in the UK on Sunday, 1 February, 2004 at 2100 on BBC Two.